Steam heating system



Aug, 9, 1932.

I. CQJENNINGS ET AL STEAM- HEATING SYSTEM Filed July 18, 1930 of thesystem.

Patented Aug. 9, 1932 UNETE STATES IRVING C. JENNINGS, OF SOUTH NORWALK,

CONNECTICUT, AND LOUIS W. SOUTHG-ATE,

OF WASHINGTON, DISTRICT OF COLUMBIA; SAID SOUTHGATE ASSIGNOR TO SAIDJENNINGS.

STEAM HEATING SYSTEM Application filed July 18,

The object of this invention is to improve steam heatingsystems and makethem safer in operation, particularly at low temperatures. The inventionhas especial application to vacuum steam heating systems.

A vacuum steam heating system comprises a source of steam supply, as aboiler or street main, a supply line, radiators, a return line, and apumping apparatus for exhausting air and gas from the system and forcreating and maintaining a vacuum or sub-atmospheric pressure in thereturn line and radiators and for handling the water of condensation by.

returning the sameto the boiler or hot well or by removing the same fromthe system.

In the art the pipe or piping forming the supply line is known as thesupply side of the system and the pipe or piping forming the return lineis known as the return side In operating such a system, a difiiculty hasbeen encountered when the steam supply is lowered or shut off, as by theshutting down of an oil or a gas burner. In such instances, the steammay condense so rapidly in the system and the radiators, that a vacuumwill be created in the radiators and supply line which will be greaterthan the vacuum created (or which can be created)"in the return line bythe pumping mechanism. In such case, the water of condensation may beheld up in the radiators, as it is difficult for the same to flow backto the boiler through the supply line, particularly if the radiatorvalves are only partly opened or if measuring orifices and traps areused in connection with the radiators, as water will flow very slowlythrough a small opening as compared with the flow of vapor therethrough.

When this takes place, the boiler may be so depleted of water as to beburned out or explode, particularly when the system starts again inproper operation and the large quantity of water held up in theradiators is suddenly forced into the same. 7

Various expedients have been tried to overcome this difficulty, amongwhich maybe noted the following:

A shunt pipe line provided with a hand valve has been arranged betweenthe supply 1930. Serial No. 468,798.

difierences, particularly when operating at low temperatures. I V

A vacuum relief valve has sometlmes been applied to the supply line toopen when the pressure therein falls below atmospheric to admitatmospheric air into the supply line. This does" not meet the variousconditions encountered, particularly as it is common practice to run theentire system at sub-atmospheric pressures.

Another expedient that has been tried has been toarrange a check valveopening towards the supply line in the shunt pipe line between thereturn and supply lines. This does not meet all conditions because thischeck valve will open only when the pressure in the supply line is lessthan that in the return line. The dangerous condition before explained,namely the holding up of water ofvcondensation in the radiators mayoccur when the supply and return sides of the system are balanced orwhen the pressure in the supply line is only a little more than in thereturn line. v

To meet all conditions and make the 'system absolutely safe, thefollowing arrangement has been invented: v A valve is arranged so thatatmospheric air can be admitted therethrough intothe supply side of thesystem, and the opening and clos ing of this valve is governed so as toprevent the pressure in the supply side from falling below the pressurein the return side of the system. I

This governing action is preferably obtained from the differential ofpressure between the supply and return sidesvof the system. 1

When'the pressure in the supply side falls 7 to a point dangerously nearthe pressure in the 1 line than in the .return line and the pump.

return side, the valve will open and atmospheric air will be admitted tothe supply side. The term pressure as used in the previous descriptionhas been employed to designate absolute pressures, irrespective of thepartial vacuum or sub-atmospheric pressure derived from the pumpingapparatus, These partial vacuum pressures are usually measured by amercury column, thirty inches thereon approximately representing theatmospheric pressure of fifteen pounds per square inch and a two inchdrop thereon showing a minus pressure relatively to atmospheric pressureof one pound per square inch. 1

Adjusting mechanism is provided so that the operation of the means foroperating the valve can be regulated, and this mechanism is preferablyset so that the valve will open before the pressure in the supply sidefalls to the pressure in the return side, whereby the pressure in thesupply will always exceed the pressure in the return side by adetermined amount. By this;v arrangement,

pressure will always exist in the supply side 7 relatively to the returnside so that there al ways will be a circulation through the radiatorstowards the return sideo-f the system to For example, suppose thepumping mechanism is set to create and maintain twelve inches of vacuumor a minus pressure of six pounds per square inch relatively to atmos-Suppose the adjusting valve will open when eleven inches of vacuum iscreated in the supply line or when the differential of pressures betweenthe supply side and the return side is less than one inch of mercury orone-half pound per square inch. When the valve opens, enough atmosphericair at fifteen pounds will be admitted into the supply side to preventthe vacuum therein falling below eleven inches and proper circulationthrough the radiators will thus be insured. vThe operation ofthe valvewill be in effect that of a pressure regulator, using atmospheric air asthe source of pressure,

and operating sothat the pressure in the sup ply line can never fallbelow the-pressure in the return line by the constantobtained by theadiustment, Thus with the empirical figures stated,

there always will be at least one-half pound per square inch morepressure in the supply proper circulation will always bemaintained. V

The atmospheric air thus admitted into the supply side of thesystem willbe ejected therefrom by the vacuum pump after it circulates throughtheradiators and return line. This air will help the operation as it willtend to cool the system, and the radiators, which is desirable, as thedangerous condition before detailed is usually encountered when the'boiler is continually being shut down as on warmdays.

The operation has been described in terms of the absolute pressures usedin vacuum steam heating systems, wherein the pumping apparatus is set tomaintain a vacuum in the return side of the system.

The inlet for atmospheric air for the above stated purpose is preferablyprovided with an inwardly opening check valve, so that if it is desiredto operate the system above subatmospheric pressures, steam aboveatmospheric pressure will not be allowed to escape from the systemthrough the valve.

One specific application of our invention is illustrated in theaccompanying drawing, in which p Fig. 1 is a diagrammatic view of avacuum steam heating system with our invention applied thereto; and

Fig. 2 is a sectional view on an enlarged the'return line and radiators,and the water oficon'densation handled or forced back to the boiler orhot well or removed from the yst m- A pressure regulator F maybearranged inthe supply line. These parts represent an ordinary vacuumsteam heating system and needno further: description. The valveG formingour invention will now be described. This valve'comprises a casing. 10having a diaphragm 11 arranged therein'which is connected to a valve 12,coacting with a seat 13. The supply line B is connected to the casing 10above the diaphragm by a pipe 14, and the return line D is connected tothe casing 10 below the diaphragm by a pipe 15. r

The stem of the valve 12 is extended to fit into a screw plug 16 adjustably threaded into the bottom of the casing 10 and a clamp nut 17 isthreaded on the screw plug 16. A spring 18 is arranged on the valve stembetween the screw plug 16 and the diaphragm 1-1. This spring tends toopen the valve 12 and the screw plug 16 preferably is adjusted so thatthespring will overcome the atmospheric pressure on top of the valve'andcause L throughout the system under all conditions of vacuum and waterof condensation will not be held up in the system.

Thus a very simple mechanism is provided for the purposes stated.

lVhile we have shown one form of apparatus for practicing our invention,We are aware that the same may be practiced in many other ways and we donot wish to be limited to the details of construction herein shown anddescribed.

Having thus fully described our invention, what we claim and desire tosecure by Letters Patent is 7 1. In a steam heating system having aradiator, a supply line to the radiator and a return line from theradiator, a valve connected to admit atmospheric air to the supply lineand means governing the operation of the valve to prevent the pressurein the supply line from falling below the pressure in the return line.

2. In a steam heating system having a radiator, a supply line to theradiator and a return line leading from the radiator, a valve connectedto admit atmospheric air to the supply line, and means -for governingthe operation of the valve by the differential of pressures between thesupply and'return lines a of the system.

3. In a steam heating system having a radiator, a supply line to theradiator and a return line leading from the radiator, a valve connectedto admit atmospheric air to the sup- 7 ply line, means for governlng theoperation eration of the valve bythe differential of pressures betweenthe supply and return lines of the system, said means being adapted toopen the valve before the pressure in the sup ply line falls below thepressure in the return line of the system.

5. In a vacuum steam heating system, the combination of a source ofsteam supply, radiators, a supply line to the radiators from saidsource, a return line from the radiators, a pumping apparatus forexhausting air and gas from'the system and handling the water ofcondensation and a valve connected to admit atmospheric air into thesupply line governed by the differential of pressures between the supplyand return lines.

- 6. In a vacuum steam heating system, the combination of a source ofsteam supply, radiators, a supply line to the radiators from saidsource, a return line from the radiators, a pumping apparatus forexhausting air and gas from the system and handling the water ofcondensation, a valve connected to admit atmospheric air into the supplyline, governed by the differential of pressures between the supply andreturn lines, and means for controlling the ope-ration of said valve.

7 In a steam heating system having a radiator, a. supply line to theradiatorand a return line from the radiator, a valve con,

nected to admit atmospheric air into the supply line, means governingthe operation of the valve to prevent the pressure in the supplylinefrom falling below the pressure in the return line in the system,and a check valve for preventing an outward flow through said valve.

8. In a vacuum steam heating system, the combination of a source ofsteam supply, radiators, a supply line to the radiators from saidsource, a return line from the radiators, a pumping apparatus forexhausting air and gas from the system and handling the Water ofcondensation, a valve connected to admit atmospheric air into the supplyline, and a diaphragm for operating said valve exposed on one side tothe pressure in the supply line and on the other side to the pressure inthe return line. a

9. In a vacuum steam heating system, the combination of a source ofsteam supply, radiators, a supply line to the radiators from saidsource, a return line from the radiators, a pumping apparatus forexhausting air and gas from the system and handling the Water ofcondensation, a valve connected to admit atmospheric air into the supplyline, a diaphragm for operating said valve exposed on one side to thepressure in the supply line and on the other side to the pressure in thereturn line, and a spring for helping the diaphragm l open the valve.

10. In avacuum steam heating system, the combination of a source ofsteam supply, radiators, a supply line to the radiators from saidsource, a return line from the radiators, a pumping apparatus forexhausting air and gas from the system and handling the water ofcondensation, a valve connected to admit atmospheric air into thesupplyline, a diaone side to the pressure in the supply line and on theother side to the pressure in the return line, a spring for helping thediaphragm open the valve, and means for adjusting the action of thespring.

11. 'In a vacuum steam heating system, the combination of a source ofsteam supply, radiators, a supply line tothe radiators from said source,a return line from the radiators, a pumping apparatus for exhausting airand gas from the system and handling the water of condensation, a valveconnected to admit atmospheric air into the supply line, a diaphragm foroperating said valve exposed on one side to the pressure in the supplyline and on the other side to the pressure in the return line, a springfor helping the diaphragm open the valve, and means for adv j usting theaction of the spring so that the valve will open before the pressure inthe supply falls below the pressure in the return line.

In testimony whereof we have hereunto affixed our signatures.

' IRVING 0. JENNINGS.

LOUIS W. SOUTHGATE.

